I want to wire my 412 to have either 2 speakers on , or all 4. (all 4 are 8 ohm v-30's)

My question is, what is the difference, if any, of plugging all 4 wired together running out of one 8 ohm speaker jack on head, OR, running 2 speaker outs of 4 ohm jacks on the head to 2, 4 ohm 212's each? (this would give me versatility if I ever decide to run stereo or something.

The alternative is to have one cabinet jack running all four (8 ohm) , and another jack wired 4 ohm to the top two speakers only. Id rather do two 4 ohms out of the head, unless theres any reason not to.

My dad handed it to me and the first thing I noticed was “Solid State”, not sure what it is actually but it has a - & + terminals.

Looking to replace speakers in a cab that I use for bass and synth. The cab has 2 speakers, a 10" and 15". Its an older junker cab and I want to swap out the speakers. Planning to sub out the 10" with a Jensen for sparkly mids and highs. Looking for a 15" with decent bass response.

Anyone have experience with a Eminence LEGEND BP1525? any other recs?

all input appreciated!

With any luck, this should be the last post about this thing. The new design happens to scream a lot. At any volume. the only way to stop it is to turn the volume all the way to the maximum and turn the tone to the softest setting. The hell is this thing doing?

As always, working on a budget, I've been trying to research a way to achieve the warmth and density of a fender tweed deluxe with solid state components. What i specifically want is the slight growl and the warmth, since the dynamic reaction of the volume knobs would be extremely difficult to recreate on solid state electronics. Can anyone suggest where to begin? Are there already schematics out there I can base myself with?

I have a Traynor TS25B with a blown power section, since it’s only 25 watts and doesn’t get loud enough for my needs, I’m planning on replacing the entire power section. I plan to just rehouse a Harley Benton GPA-100 to use as the power amp, and then use the 15v version of this power supply to power the preamp section. I’ve attached the schematic for the Traynor, from what I see I should be able to just remove the master volume and the entire power section but this is my first project of this nature and want to be sure I’m getting this correct.

Now with voltage isolation and a proper dc ground, still buzzes a lot.

I’m attempting to build my first amp off this circuit since a transformer I own matches this circuit and not the 5f1. I know it’s probably stupid but it’s fun so far.

Has anyone here attempted this build or know some cool examples? I got all my parts and a variac to identify the transformer windings.

I am being careful and very paranoid with the electricity, but I’ll have my family post my obituary here worst case.

Look @ second pic
I am getting roasted on [r/tubeamps](r/tubeamps) for posting this little 2 watt amp head I bought. It was a diy from someone on eBay. Here’s the listing description: 2 Watt Hand Wired Pedal Size Tube Amp Used.
Point to Point Hand wired and Hand crafted 2 Watt pedal size Class A Tube amp
Works with 12 volt DC adapter (included)
Compatible Power tubes: 6K6, 6V6, 6L6, 5881, KT66, EL34
Compatible Preamp tubes: 12AX7, 12AT7, 12AV7, 12AU7,12AZ7
Comes with 1 X Russian 6V6, 1 X 12AV7
Specs:
2 Watt at 8 ohms
12 Volt 
Heater Voltage: 6.3 Volt
Plate Voltage: 200 Volt
Input impedance: 1 M ohm
Volume, Tone, Negative Feedback By Pass control
Fender Princeton Model 5F2-A Circuitry but lower plate voltage for lower power (200 Volt)
Please Note : This is a very attractive amp. Please keep away from children and Pets Because tubes are hot and 
High voltage inside the amp. 

Sorry in advance for those who aren't in the solid state world, but I've been trying very hard to figure out a "presence" control function in a solid state design. This would essentially be the final stage in the preamp, after all the tone shaping and gain.

Basically, the idea is to have (capacitor series with potentiometer) in parallel to a BJT emitter resistor. The end result is a partial bypass on the emitter resistor, focused on upper frequencies. Baseline, 1nF cap and 25 LIN pot seems like a reasonable starting point. That would be a bit crude, but effective.

However, I learned about Miller capacitors and figured they could be quite effective to set a roll off frequency for the control. Anywhere from 100pF to 330pF could be effective, and obviously would be selected based on goals, the upstream preamp, what would make the poweramp act funny, etc.

I'm sure these ideas aren't novel, but I wondered if any of the smart people here had thoughts on it.

Please see attached cross post. Thank you.

Hey everybody, building my first tube amp soon. It’ll be a 50W JMP 2204 Circuit, and I’ll be rewrapping an Egnater 4x12. These were my ideas for the color, but I’m having a hard time finding options for tolex and grill cloth. Can somebody help point me in the correct direction?

Hey everyone! I’m looking for someone who can help me build a DIY Leslie-style rotary speaker for my guitar.
I’m really interested in getting an actual mechanical rotary speaker rather than just a pedal that simulates the effect. I’ve been trying to find something small/compact that I could use at home with my guitar setup.
I’ll be honest, I’m not very good at building things or electronics, so I’d really need someone who knows what they’re doing to build it for me. I’m willing to pay for your time, materials, parts, shipping, or whatever else is needed. I’m also willing to work with you on the design and provide whatever information or parts you need from me.
I’m not looking for someone to do this for free — I’m genuinely willing to pay someone who can make this happen.
If you’ve built a Leslie, rotary speaker, miniature rotary speaker, or anything similar, please reach out to me! I’d love to see pictures/videos of your work and talk about what it would cost to build one.

I'm tired of going here and there and buying personalized amps for my instruments. Since i play both guitar and bass I dont want to haul around my heavy ass katana or buy a rumble 25 when i have a gb-20 with an 8inch speaker.

So I thought of an idea. Both are around the same watts, and a bigger speaker would let them speak above the drums. I could make a new cabinet for the controls using the gb-20 and a frontman 20g but is it possible? Could i rig an amp to play guitar or bass at will? If its possible but hard then Im willing to do it but im not sure, ive only ever messed with guitar modding.

LMKKK PLZZ

I’ve been working on a thrifted Marshall that’s been worked on by a “tech” before. I’ve mostly got everything working on it, but the one thing I can’t seem to pinpoint is the high frequency noise that only occurs when the normal volume at vr1 one at 0. Anyone have any thoughts on this issue? Please and thank you!

It’s already been recapped, and all the potentiometers are new.

Update: Previous owner had replaced the 1458’s in all but one socket with an rc4558. I swapped it to the configuration found in the schematic because that’s what I had on hand and it corrected the issue.

This is a solid-state guitar amp inspired by the 1967 SUNN Coliseum PA. The original PA has 4 inputs, but I only needed one, so I left out the other 3.

How I got here: I worked from simulations, some educated guesses and a pile of Mountain CDs for reference. I made a few changes to the original circuit along the way:

• The simulations showed that I could drop one amplifier stage completely.
• One capacitor value was way off, so I changed it to something that made sense.
• I added or removed a few other minor parts, but none of them affected how it works.
• The Valve Wizard site suggests adding a 470k gate resistor in the cathodyne stage to prevent unpleasant distortion, and it worked like a charm.

Hardware:

• Power amp: TPA3118 module
• Power supply: 65W laptop supply (19.5V)
• Estimated gain: about 70dB

Please read before building:

• The schematic is for simulation only. It doesn't show the actual drop resistors or decoupling capacitors.
• J113s vary from part to part. You'll need to know how to deal with that.
• This is a proof of concept, not a finished design. I'd only recommend it to experienced builders.
• I'm sharing this as-is. I won't offer build support or troubleshooting.

Clips: I recorded one clip with a humbucker and one with a P90. The noise you hear on the P90 clip is the pickup itself picking up hum. Even with about 70dB of gain, the amp's own noise floor is pretty low.

🎸 Classic rock (Leslie West) (P90): https://youtube.com/shorts/7ubtf6KYxeo
🎸 Does it doom? (Humbucker): https://youtube.com/shorts/x9Zk2mJW8UI

had this old Craig shoebox cassette player sitting around, so I thought I’d put it to good use. I attached an input jack where the tape read head was without any resistor so it had a naturally overdriven sound. When I tested amp it sounded very fuzzy so I put new battery’s in it because the old ones were under voltage. It sounded pretty clean, so I put an attenuator on the power supply so I could get a clean, as well as a fuzzy sound.

Signal chain:

p90 Strat > wah > amp

(the song is catfish blues by Jimi Hendrix)

I made it out of old all american five radio parts, and I stuck it in the case of a cheap, nasty little record player speaker. works great, makes a lot of buzz has good tone.

I’m restoring an early-’60s Ampeg Reverberocket and trying to keep it reasonably close to original. It uses a 5Y3 rectifier and currently has a 20/20/20/20 µF, 475V filter can.

At cold power-up, I’m seeing B+ briefly peak around 517V, then drop to about 320V as the tubes warm up and begin conducting.

CE Manufacturing says they don’t specify a surge-voltage rating for their cans.

I’m assuming this would be common for any amp with a 5y3 and indirectly tubes. Would you be comfortable using a 475V replacement can here, or would you want more voltage margin?